Diagonal fan

ABSTRACT

The invention relates to a diagonal fan for gaseous media, with a diagonal impeller ( 26 ) having a carrier plate ( 33 ) with several vanes ( 36 ) arranged thereon, with a guide device ( 28 ) that is connected downstream to the diagonal impeller ( 26 ) for increasing the pressure of the medium, and with a cover plate ( 40 ), which encloses the carrier plate ( 33 ) radially and which extends, at least in sections, axially along the carrier plate ( 33 ), wherein a gap ( 43 ) is formed between the vane ends ( 37 ) of the vanes ( 36 ) on the carrier plate ( 33 ), which extend towards the cover plate ( 40 ), and wherein the vane ends ( 37 ) of the vanes ( 36 ) on the carrier plate ( 33 ) and a peripheral face ( 39 ) of the cover plate ( 40 ), which is allocated to the vane ends ( 37 ), can be positioned axially relatively to one another for adjusting a gap width S of the gap ( 43 ) with at least one axial adjustment unit ( 61 ) (see FIG.  1  for this).

This application claims priority of German Patent Application No. 10 2012 106 429.6 filed Jul. 17, 2012, which is hereby fully incorporated herein by reference.

The invention relates to a diagonal fan for gaseous media, comprising a diagonal impeller and a guide device connected to the diagonal impeller downstream to increase the pressure of the medium, as well as a cover plate.

Such a diagonal fan is known from DE 10 2010 032 168 A1. Such fans can convey a flow medium consisting of air or other gases diagonally from inside to outside. Such fans can, for example, be used at the start, within, or at the end of pipelines, wherein the use is not limited to the use of pipeline systems.

Such a diagonal fan comprises a diagonal impeller, to which a guide device is connected axially to increase the pressure of the flow medium. The diagonal fan possesses a diagonal impeller, which is formed from a carrier plate with vanes arranged thereon, which extend radially outwards in the direction of a cover plate. The cover plate is fixed to an inlet nozzle, which is arranged in turn on an external housing portion of an intake unit. The diagonal impeller is driven by a motor, wherein its motor axle bears the carrier plate. A gap is formed between the free vane ends of the vane arranged on the carrier plate and of a cover plate enclosing the vane ends radially, which is formed by mounting the carrier plate onto the motor and from the cover plate to the inlet nozzle of the intake unit. As the width of the gap increases, the efficiency of such fans decreases.

The object of the invention is to create a diagonal fan wherein the efficiency can be further improved.

This object is solved by the features of the main claim. Further advantageous embodiments and developments are specified in the further claims.

Provision is made in the diagonal fan according to the invention for the vane ends of the carrier plate and a peripheral face of the cover plates allocated to the vane ends to be able to be positioned relative to one another to adjust a gap measurement or a gap width of the gap axially with at least one axial adjustment unit. It is thus possible for a predetermined, in particular a millimal gap width, to be adjustable, such that the vane ends extend directly to the peripheral face of the cover plate, but can rotate freely on the peripheral face of the cover plate. Thus a virtually optimal conveyance of the gaseous medium can be produced via the entire flow cross-section between the cover plate and the carrier plate in a separated arrangement of the cover plate and carrier plate, without an annular flow extending in the gap between the vane ends of the vanes and the peripheral face of the cover plate being able to develop. Thus the efficiency of such diagonal fans is increased.

The diagonal fan can have the at least one axial adjustment unit between the carrier plate and a motor driving the carrier plate. The cover plate is static, so is provided fixed to the intake unit. It is thus possible to adjust the gap width by simply altering the position of the carrier plate axially or in the direction of the longitudinal axis of the diagonal fan.

Provision can alternatively be made for the at least one axial adjustment unit to be provided between the cover plate and the housing portion, or the inlet nozzle of the intake unit containing the cover plate. The carrier plate is static, so is provided fixed to a drive axle of the motor. In the same way, this embodiment enables the cover plate to be provided axially for the adjustment of the gap width relative to the fixed carrier plate.

A further alternative embodiment of the invention provides the axial adjustment unit between one of the motor covers arranged on the housing portion and a motor driving the carrier plate. This embodiment also enables gap adjustment between the carrier plate and the cover plate in the same way as the preceding embodiment.

A further alternative embodiment of the invention provides an axial adjustment unit between a housing portion of the guide device and a motor cover surrounding a motor. This provides a further alternative for adjusting the gap between the vanes of the carrier plate and the cover plate.

A further alternative embodiment provides for the at least one axial adjustment unit to be provided between the carrier plate and the motor driving the carrier plate and/or between the cover plate and the housing portion or the inlet nozzle of the intake unit containing the cover plate and/or between a motor cover and the motor and/or between a housing portion of the guide device and a motor cover surrounding the motor. Thus the carrier plate and/or the cover plate and/or the motor and/or the motor cover can be altered and adjusted axially in the axial position between a motor cover and the motor and/or between a housing portion of the guide device and a motor cover surrounding the motor. In such an embodiment, wherein one of four, two of four, three of four or all four adjustment possibilities are optionally provided, increased flexibility in the adjustment of the gap width is provided.

The axial adjustment unit can have at least one adjustment element, with which the carrier plate can be adjusted continuously with respect to the motor or the cover plate can be adjusted with respect to the housing portion or to the inlet nozzle of the intake unit. Thus, depending on the production tolerance of the components, an exact alignment of the adjustment can be carried out to a predetermined clearance or a millimal clearance.

The adjustment element of the axial adjustment unit can be arranged in an axial position with respect to the motor on the one hand, or with respect to the housing portion or to the inlet nozzle on the other, in a pre-stressed state with an energy storage element. This enables clearance-free adjustment, whereby increased precision in the adjustment of the carrier plate and the cover plate is enabled with respect to one another.

A security device is preferably provided for the permanent fixing of the adjustment element of the axial adjustment unit after the gap width has been adjusted. This is formed, for example, as a clamping device, which enables the adjustment element to be fixed releasably. Thus a subsequent alignment can be simply enabled, for example by servicing or exchanging. This clamping device can be formed as security from a synthetic thread section, for example in an adjustment unit comprising a screw thread. Alternatively, a bonded or weld connection can be applied to secure to the adjustment element after the gap width has been adjusted. In particular, bonded connections can enable a subsequent release for the exchange or later adjustment of the gap width.

The axial adjustment unit can, for example, be formed as an adjustment element by a screw connection with an adjusting screw. Depending on a rotational movement of the adjusting screw, actuation towards and away from the axial direction can be determined exactly. Provision can alternatively be made for the axial adjustment unit to be formed by a fastener connection, wherein the adjustment element comprises, for example, a tension rod. This arrangement likewise enables a tension rod to be immersed continuously into a receiver, for example on a drive axle of the motor. Likewise, the tension rod can also encompass a drive axle of the motor.

The adjustment element of the axial adjustment unit, which is provided between the carrier plate and the motor, preferably comes into contact with a driveshaft of the motor, such that the carrier plate is fixed to the driveshaft of the motor. Thus a constructively simple design can be enabled, such that the positioning of the axial adjustment unit is located centrally on or in the driveshaft of the motor. Thus an imbalance-free arrangement can be created. Provision can alternatively be made for a coupling element to be able to be arranged on the driveshaft, with which the adjustment element of the axial adjustment unit comes into contact. It is thus possible to refit an axial adjustment unit in existing diagonal fans.

The adjustment element of the axial adjustment unit is preferably designed as an external thread between the cover plate and the housing portion or the inlet nozzle, which comes into contact with an internal thread of the housing portion or the inlet nozzle of the intake unit. Continuous adjustment can thus also be enabled for the cover plate. Alternatively, instead of the thread, a fastening or clamping connection can also be provided so as to fix the cover plate axially in an adjusted position with respect to the housing portion or to the inlet nozzle of the intake unit.

As an alternative to the continuously adjustable axial adjustment unit, the axial adjustment unit can also be adjustable to predetermined gradations. Simple mounting is thus enabled, without any adjustment effort.

In order to embody continuous adjustment, the adjustment element is designed, for example, as a fitting pin, fitting key or fitting protrusion, which can be arranged in stepped recesses, in individual depressions arranged alongside one another or openings on the carrier plate, cover plate, inlet nozzle or driveshaft having axial depths that are different from one another. Thus a form-fit connection can simultaneously be created radially. The depressions, openings or suchlike are aligned according to the contour of the fitting pin, fitting key or fitting protrusion, such that, for example, after the carrier plate has been positioned on the driveshaft of the motor, the carrier plate is aligned both radially and axially with respect to the driveshaft. The same applies for the positioning of the cover plate with respect to the housing portion or the inlet nozzle of the intake unit.

The axial adjustment unit can comprise an adjustment element for stepped adjustment of a gap width, which is designed as an adjusting screw or tension rod, on which at least one spacing element can be positioned, wherein spacing elements are provided with predetermined lengths that are different from one another. Thus, after having determined the gap widths that are to be adjusted, a spacing element having a predetermined length can be selected and positioned on the adjustment unit, such that there is simplified mounting in conjunction therewith. Particularly for parts which are from the same batch, a considerable amount of time is saved during mounting.

The invention and further advantageous embodiments and developments of the same are described and illustrated in greater detail below by means of the examples depicted in the Figures. The features that are to be gleaned from the description and Figures can, according to the invention, be applied individually or together in any combination. The following are shown:

FIG. 1 a schematic sectional view of a diagonal fan according to the invention,

FIG. 2 a schematically enlarged view of detail X in FIG. 1,

FIG. 3 a schematically enlarged view of detail Y in FIG. 2,

FIG. 4 an alternative embodiment of an axial adjustment unit to FIG. 3,

FIGS. 5 a to 5 f schematic views of further alternative embodiments to FIGS. 3 and 4,

FIG. 6 a schematically enlarged view of detail Z in FIG. 1,

FIG. 7 a schematically enlarged view of detail A in FIG. 6,

FIGS. 8 a and 8 b a schematic detailed view of alternative embodiments to FIG. 7,

FIG. 9 a schematic sectional view of a further alternative embodiment to FIG. 1,

FIGS. 10 a and 10 b schematic views of a further alternative embodiment to FIG. 9,

FIG. 11 a schematic local section of a further alternative embodiment to FIG. 9, and

FIG. 12 a schematic local section of a further alternative embodiment to FIG. 9.

A schematic sectional view of a diagonal fan 11 is depicted in FIG. 1, which comprises an external housing portion 12, in particular a housing sheath, which encloses a straight, circularly cylindrical cylinder interior. A right and a left flange 17, 18 are applied in a fixed manner to its respective left and right-hand end walls 14, 15 outside of the housing portion 12. A schematically depicted pipeline 21, 22 can be connected at both ends of the housing portion 12 respectively, and thus to the diagonal fan 11, by means of this flange 17, 18. The diagonal fan 11 can thus be constructed between these pipelines 21, 22. An external diameter of the pipelines 21, 22 can also correspond to the external diameter of the housing portion 12. The pipelines 21, 22 can also respectively have a diameter differing from the diameter of the housing portion 12 and be connected to the diagonal fan 11 via a corresponding conduit adaptor.

The diagonal fan 11 possesses a diagonal impeller 26 which is allocated upstream of an intake unit 29. A guide device 28 and a diffuser 30 connected thereto are designed within the diagonal fan 11 downstream of the diagonal impeller 26. The diffuser 30 is formed by an blow-out unit 31. The gaseous flow medium, which is pressurised through the diagonal fan 11 by means of the diagonal impeller 26, flows around a central interior space of the diagonal fan 11, which is defined inwardly by a carrier plate 33 of the diagonal impeller 26 and by an intermediate casing 34 which is connected in an aerodynamically efficient manner to the carrier plate 33. The carrier plate 33 axially bends downstream, such that the intermediate casing 34 adjoins this in an axial direction in an aerodynamically efficient manner. The flow medium thus flows past radially outside the carrier plate 33 and the intermediate casing 34.

At its periphery, the diagonal impeller 26 possesses spaced vanes 36, which are fixed by their one end to the carrier plate 33. Opposite this, free vane ends 37 of the vanes 36 point towards a peripheral face 39 of a cover plate 40, which is fixed to the housing portion 12. The vanes 36 are, for example, profiled as a cross-section and designed three-dimensionally curved. The upstream insertion edges of the vanes 36 are aligned approximately perpendicular to the flow direction of the ventilating flow medium and possess a corner arc. The upstream trailing edge of the vanes 36 is likewise aligned approximately perpendicular to the diagonal flow which is departing downstream. The cover plate 40 can form a piece of an inlet nozzle 41. Alternatively, the inlet nozzle 41 can be fixed to the housing portion 12 and can encompass or support the cover plate 40, such that an aerodynamically efficient transition is provided from the intake unit 29 to the guide device 28. If the inlet nozzle 41 and cover plate 40 are each embodied separately, an annular gap is produced in-between, which can be sealed off by a sealing element. Alternatively, such an annular gap can also be embodied as a flow labyrinth.

The flow leaving the diagonal impeller 26 then flows through the region of the guide device 28. In this section of the diagonal fan 11, stationary guide vanes 45 are arranged peripherally and spaced between the intermediate casing 34 and the housing portion 12. The flow leaving in a helical, diagonal direction of the diagonal impeller 26 is diverted to an axial flow direction by the guide vanes 45. Just like the vanes 36 of the diagonal impeller 26, the guide vanes 45 in the present example are also profiled and designed three-dimensionally curved. Alternatively, the profiling could be dispensed with for the vanes 36 and/or the guide vanes 45.

A motor 50 is located in the interior space 47 formed by the carrier plate 33 of the diagonal impeller 26 and by the intermediate casing 34 of the guide device 28, with said motor driving the diagonal impeller 26 by means of a driveshaft 51. The motor 50 is flange-mounted on a motor holder, which extends from the intermediate casing 34 to the interior space 47.

The diffusor 30 is embodied as being connected to the guide device 28 downstream of the same. The diffusor 30 is constructively implemented by a annular flow channel which increases the further downstream it is, and which is between a motor cover 54 and a housing wall 56 of the blow-out unit 31. The motor cover 54 is fixed to the intermediate casing 34 of the guide device 28 by means of several screws which are not depicted here, and it closes off the interior space 47 downstream.

A schematically enlarged detailed view X according to FIG. 1 is depicted in FIG. 2. The carrier plate 33 of the diagonal impeller 26 is fixed to the motor 50, in particular to the driveshaft 51, via an axial adjustment unit 61. The axial adjustment unit 61 enables axial adjustment along the axis 62, which forms a longitudinal axis of the diagonal fan 11. Adjustment to a gap measurement S between the free vane ends 37 of the diagonal impeller 26 and the peripheral face 39 of the cover plate 40 is carried out by an axial shift movement according to arrow 63 of the carrier plate 33 relative to the driveshaft 51. A millimal gap S can be adjusted by an axial shift movement of the carrier plate 33 to the right, so against the flow direction of the medium, such that a circular annular gap between the free vane ends 37 and the peripheral face 39 of the cover plate 40 is virtually eliminated.

The arrangement of the axial adjustment unit 61 between the diagonal impeller 26 and the motor 50, in particular between the carrier plate 33 and the driveshaft 51, provides a possibility to adjust the gap with S of a rotating diagonal impeller 26 with respect to an existing cover plate 40 having a peripheral face 39.

A schematically enlarged view of detail Y in FIG. 2 is depicted in FIG. 3. This schematic view shows a first exemplary embodiment of the axial adjustment unit 61. This axial adjustment unit 61 is designed continuously. For this, this comprises an adjustment element 65, designed as a screw, which is inserted into a threaded hole 66 in the driveshaft 51. So as to be fixed to the driveshaft 51, the carrier plate 33 comprises a receiver 68 which is designed in the form of a sleeve and which extends from an internal front face of the carrier plate 33 downstream towards the motor 50. This receiver 68 encompasses the driveshaft 51, such that the carrier plate 33 is fixed to the driveshaft 51 in the manner of a pivot bearing. An energy storage element 72 is preferably provided between a base 69 in the receiver 68 and a front face 71 of the driveshaft 51, through which the carrier plate 33 is received with the receiver 68 in a pre-stressed state with respect to the driveshaft 51. This energy storage element 72 is designed, for example, as a pressure spring, in particular a helical pressure spring. Alternatively, the energy storage element can also be embodied by an elastically flexible sleeve or suchlike, so as to generate the pre-stressing between the driveshaft 51 and the carrier plate 33. Clearance-free adjustment of a gap in the carrier plate 33 with respect to the driveshaft 51, in particular to the front face 71 of the drive shaft 51, can thus occur, whereby the size of the gap S, as is depicted in FIG. 2, is in turn determined. The gap width S is determined by an immersion depth of the driveshaft 51 into the receiver 68 of the carrier plate 33. Due to the action of force during the operation of the diagonal fan 11 on the vanes 36 and thus the carrier plate 33, which function upstream, the carrier plate 33 is pulled in the same direction as the one in which the energy storage element 72 functions, so against the flow direction of the medium. It is thus not necessary for there to be a catch in the downstream direction.

For securing of a gap width S, provision is made for the axial adjustment unit 61 to have a security unit 74. This can occur, according to the exemplary embodiment in FIG. 3, by a clamping section in a screw thread, wherein, for example, provision is made for synthetic material to be used which secures the adjustment element 65 from autonomous release. Alternatively, the adjustment element 65 can also be fixed by a bonded connection in the threaded hole 66. Such a bonded connection can be released again by applying a predetermined torsional force.

The carrier plate 33 preferably has a frontal depression 76, such that, when adjustment element 65 is designed as a screw, the screw head is arranged as being countersunk therein. The depression 76 can be sealed by a protective cover, which is not depicted in further detail, such that the carrier plate 33 has a completely closed off external outline and is designed to be aerodynamically efficient.

This axial adjustment unit 61 is advantageous in that release is provided close to the axis. This axial adjustment unit 61 can be used without additional balancing. Furthermore, a central connection to the driveshaft 51 of the motor 50 is provided.

Alternatively, a complementary arrangement can also be provided, wherein the driveshaft 51 encompasses the receiver 68 of the carrier plate 33, wherein an exterior energy storage element 72 is arranged.

An alternative embodiment of a continuous axial adjustment unit 61 to FIG. 3 is depicted in FIG. 4. In this embodiment, provision is made for the driveshaft 51 to have a diametrically tapered end adaptor 79, to which a thread is applied, such that this end adaptor 79 with a thread added to it forms the adjustment element 65. The receiver 68 of the carrier plate 33 comprises an internal thread, such that the carrier plate 33 can in turn be fixed onto the driveshaft 51 by a screw connection. An energy storage element 72 is in contact with a front face between the driveshaft 51 and the tapered end adaptor 79, which rests on an opposite front face of the receiver 68 of the carrier plate 33. Thus, in the same way as FIG. 3, a pre-stressed receiver 68 of the carrier plate 33 can in turn take place with respect to the driveshaft 51, wherein the construction presently leads to a clearance-free axial adjustment unit 61. Securing the position of the carrier plate 33 to the driveshaft 51 can in turn take place, for example, by means of a security element 74.

An alternative embodiment of the axial adjustment unit 61 to FIGS. 3 and 4 is depicted in FIG. 5 a. The axial adjustment unit 61 enables stepped adjustment of the gap between the carrier plate 33 and the motor 50. Instead of an energy storage element 72 according to FIG. 3, a spacing element 78 is provided, which is designed as an inflexible sleeve with a defined length. Several spacing elements 78, which are provided in predetermined lengths, can be provided for adjusting the gap width S, such that the appropriate spacing element 78 is determined and used after the diagonal impeller 26 has been positioned, for example, by means of an adjustment gauge to the cover plate 40, so as to adjust the carrier plate 33 with the vanes 36 exactly to the gap width S. This embodiment incidentally corresponds to the construction of the embodiment in FIG. 3, to which reference is made. The use of the spacing elements 78 can also be provided in the alternative embodiment according to FIG. 4.

A schematic lateral view of a further alternative embodiment of the axial adjustment unit 61 is depicted in FIG. 5 b, which enables stepped gap adjustment and thus adjustment of a gap width. The adjustment element 65 is designed as an adjustment adaptor 82, for example, which is provided prominently on the receiver 68 of the carrier plate 33. The receiver 68 encompasses a driveshaft 51, which is designed in a stepped manner, having a tapered end adaptor 79, which engages with the receiver 68. Additionally, in the driveshaft 51, a stepped recess 81, which extends radially towards the end adaptor 79, is provided. Depending on the positioning of the adjustment element 65 in the recess 81, a difference gap from the one between the receiver 68 and the driveshaft 51 can be adjusted, and thus the gap width S can be determined. The locational securing of the adjustment element 65 to the driveshaft 51 can take place by means of an additional security element or axial tensioning by a locking screw. Provision is preferably made for the adjustment element 65 to rest against a tread of the stepped recess 81 at its narrow side, which points in the direction of the drive of the driveshaft 51.

A further alternative embodiment of an axial adjustment unit 61 to FIG. 5 b is provided in FIGS. 5 c and 5 d, with which stepped adjustment of the gap width S is enabled. A fitting key 83 is, for example, inserted or injected into the tapered end adaptor 79 on the driveshaft 51 as an adjustment element 65. Frontally open, U-shaped depressions 84 are provided on the receiver 68 of the carrier plate 33, for example in the form of milled slots with different axial depths. Thus, by allocating a specific depression 84 to the adjustment element 65, the immersion depth of the receiver 68 on the carrier plate 33 onto the end adaptor 79 of the driveshaft 51 can be determined and thus the gap width S can be defined.

A further alternative embodiment to FIGS. 5 c and 5 d is depicted in FIGS. 5 e and 5 f. This embodiment differs to the effect that, instead of a fitting key 83, a fitting pin 85 is provided as an adjustment element 65 in the end adaptor 79. Frontally open openings 87 are provided on the receiver 68 of the carrier plate 33, which extend completely along the wall thickness of the receiver 68. These openings 87 are, in principle, arranged and designed in the same way as the depressions 84. The receiver 68 can be positioned with a further axial depth with respect to the end adaptor 79 by rotating the carrier plate 33 radially, such that there is an increase in the gap width S. There is thus a decrease in the gap width S in the opposite rotational direction, since the carrier plate 33 opposite the driveshaft 51 is adjusted axially in the flow direction.

In FIG. 6, the cover plate 40 with the axial adjustment unit 61 is arranged moveably with respect to the housing portion 12 according to arrow 63, so as to adjust a gap width S. In this embodiment, provision is furthermore made for the diagonal impeller 26 to be fixed statically to the driveshaft 51 of the motor 50. Thus can the adjustment of the gap width S only take place by positioning the cover plate 40 along the longitudinal axis 62 to the housing portion 12. For this, the cover plate 40, with an end pointing towards the front wall 15, rests against a housing portion 12 or is guided in a longitudinally displaceable manner therein. Opposite this, the cover plate 40 can be received by the axial adjustment unit 61 in a longitudinally displaceable manner to the housing portion 12. A transposed arrangement is also possible.

A schematically enlarged view A according to FIG. 6 of an axial adjustment unit 61, which is only depicted schematically, is depicted in FIG. 7 in an enlarged state. The axial adjustment unit 61 is designed, for example, as a continuous gap adjustment in the same way as FIGS. 3 and 4. The adjustment element 65 is, for example, designed at an end of the cover plate 40 pointing towards the guide device 28 as an external thread, and engages with an internal thread of the housing portion 12. Thus, in turn, an axial shift movement according to arrow 63 is produced, whereby the peripheral face 39 of the cover plate 40 can be moved towards or away from the vane ends 37 of the vanes 36. Additionally, a final strike can be provided on the housing portion 12, such that the axial adjustment movement 61 is limited downstream. Alternatively, the adjustment element 65, instead of a thread, can also be embodied by a tensioning device, wherein, for example, an end section of the cover plate 40, which is pointing towards the guide device 28, is tensioned with the housing portion 12, wherein graduations can additionally be provided axially so as to enable axial locational security.

An alternative embodiment of the axial adjustment unit 61 to FIG. 7 is provided in FIG. 8 a, which enables axial stepped adjustment of a gap between the cover plate 40 and the housing portion 12. The typical embodiment of this axial adjustment unit 61 according to FIG. 8 a corresponds to the axial adjustment unit 61 described in FIGS. 5 c and 5 d, to which reference is made. Alternatively, the axial adjustment unit 61 according to FIG. 8 a can also be designed in the same way as the embodiment in FIGS. 5 e and 5 f.

A further alternative axial adjustment unit 61 for stepped adjustment of the gap width S to FIG. 8 a is depicted in FIG. 8 b. This axial adjustment unit 61 corresponds to the axial adjustment unit 61 described in FIG. 5 b, to which reference is made.

According to an embodiment which is not depicted, the diagonal fan 11 can have an axial adjustment unit 61 for both the carrier plate 33 and the cover plate 40 respectively, which enables continuous adjustment, or, alternatively, stepped adjustment. Likewise, provision can be made for a combination of a continuous axial adjustment unit 61 and a stepped axial adjustment unit 61 to be provided, meaning that, for example, the cover plate 40 can be adjusted by a stepped axial adjustment unit 61 and the carrier plate 33 can be adjusted by a continuous axial adjustment unit 61 in the axial position along the longitudinal axis 62 of the diagonal fan 11. Likewise, a transposal of the axial adjustment units 61 can also be provided. If both the carrier plate 33 and the cover plate 40 can each be adjusted axially, both alone and independently of one another by at least one axial adjustment unit 61, flexible adjustment can be enabled independent of installation situations and the accessibility thereof.

A schematic sectional view of an alternative embodiment of the diagonal fan 11 to FIG. 1 is depicted in FIG. 9. This embodiment differs from the embodiment in FIG. 1 only in terms of the positioning and arrangement of the axial adjustment unit 61. The construction of the diagonal fan 11 is incidentally the same, such that reference is made to the aforementioned description in full.

The axial adjustment unit 61, instead of the positioning according to FIG. 1 between the carrier plate 33 and the driveshaft 51 of the motor 50, is now provided on the opposite side between the motor 50 and the motor cover 54. Thus can the axial adjustment unit 61 be arranged on a front face 92 of the motor and come in contact with the motor cover 54. Alternatively, the axial adjustment unit 61 can be provided on the external periphery of the motor 50 and engage with the frontal end of the motor cover 54 or with a section of the motor cover 54 which is radially peripheral or which encloses the motor 50.

In the exemplary embodiment according to FIG. 9, a spacing element 91 is provided on the front face 91 of the motor housing, which engages with the front face 93 of the motor cover 54. This spacing element 91 can be designed as a prefabricated plate having a predetermined thickness, such that, by exchanging the spacing elements 91 with various thicknesses, the desired gap width S between the vanes 36 of the diagonal impeller 26 and the peripheral face 39 of the cover plate 40 can be adjusted. Alternatively, the spacing element 91 can consist of several individual elements that are designed as plates, which have the same and/or different thickness, such that the desired thickness of the spacing element 91 can be formed from the sum of the individual plates.

An alternative embodiment of the axial adjustment unit 61 to FIG. 9 is depicted in FIGS. 10 a and 10 b. For example, a segmented plate element 94 can be provided on the front face 92 of the motor cover 54, wherein the individual segments have different thicknesses. These can, for example, be fitted to a base plate and assembled according to the installation options. An adjusting element 95 is provided on the front face 92 of the motor housing 52, which has at least two contact surfaces corresponding to the contour of the segments of the segmented plate element 94. Thus, by rotating the motor 50 around the motor axis 62, a different gap between the adjusting element 95 and the segmented plate element 94 can be adjusted, wherein the motor 50 is clamped tightly after the axial gap has been adjusted by this axial adjustment unit 61.

A further alternative embodiment of the axial adjustment unit 61 to FIG. 9 is depicted in FIG. 11. Here, a thread is provided between the motor housing 52 and a peripheral section of the motor cover 54, by which, in turn, there can be axial adjustment of the gap S.

An alternative embodiment to FIG. 11 is depicted in FIG. 12. Provision is made in this embodiment for a cylindrical section of the motor housing 52 to be immersed into a complementary section on the motor cover 54 and to be guided therein, and for example, for the axially adjusted position to be fixed by a security element such as a security screw. The axial adjustment unit 61 thus comprises a cylindrical section of the motor housing 52 and a cylindrical section on the motor cover 54 which is adapted thereto, as well as security elements or clamping elements for securing the adjusted maximum position of the motor 50 to the motor cover 54.

A further embodiment, which is not depicted in greater detail, provides an axial adjustment unit 61 between the housing portion 12 and the motor cover 54. Thus, the motor cover 54 can be received in an axially displaceable manner relative to the housing portion 12, whereby, in turn, the gap width S between the vane ends of the vanes 36, from the carrier plate 33 to the peripheral face 39 of the cover plate 40, can be adjusted.

It is understood that any combination of the axial adjustment units 61, including with respect to their positioning within the diagonal fan 11 and with respect to their embodiment, is also possible, meaning that only one, two, three or four axial adjustment units 61 can be provided. 

1. Diagonal fan for gaseous media having a diagonal impeller, which has a carrier plate having several vanes arranged thereon, having a guide device connected downstream to the diagonal impeller for increasing the pressure of the medium and having a cover plate, which encloses the carrier plate radially and which extends axially, at least in sections, along the carrier plate, wherein a gap is formed between the vane ends of the vanes on the carrier plate, which extend in the direction of the cover plate, and the cover plate, wherein the vane ends of the vanes on the carrier plate and a peripheral face of the cover plate, which is allocated to the vane ends, is positioned relative to one another for adjusting a gap width S of the gap axially with at least one axial adjustment unit.
 2. Diagonal fan according to claim 1, wherein the at least one axial adjustment unit is provided between the carrier plate and a motor that drives the carrier plate, and in that the cover plate is provided statically on a housing portion of an intake unit.
 3. Diagonal fan according to claim 1, wherein the at least one axial adjustment unit is provided between the cover plate and a housing portion or on an inlet nozzle of an intake unit, and in that the carrier plate is provided statically on the driveshaft of the motor.
 4. Diagonal fan according to claim 1, wherein the axial adjustment unit is provided between a motor cover arranged on the housing portion of the guide device and a motor that drives the carrier plate.
 5. Diagonal fan according to claim 1, wherein an axial adjustment unit is provided between a housing portion of the guide device and a motor cover that encloses a motor.
 6. Diagonal fan according to claim 1, wherein the at least one axial adjustment unit is provided between the carrier plate and a motor that drives the carrier plate and/or between the cover plate and a housing portion or on an inlet nozzle of an intake unit and/or between a motor cover and the motor and/or between a housing portion of the guide device and a motor cover that receives a motor.
 7. Diagonal fan according to claim 1, wherein the axial adjustment unit has at least one adjustment element, with which the carrier plate is adjustable continuously with respect to the motor, or the cover plate with respect to the housing portion or to the inlet nozzle of the intake unit.
 8. Diagonal fan according to claim 7, wherein the adjustment element of the axial adjustment unit is arranged with an energy storage element in a pre-stressed state in an axial position to the motor or housing portion or inlet nozzle of the intake unit.
 9. Diagonal fan according to claim 7, wherein the adjustment element of the axial adjustment unit is secured with a security unit, in particular a releasable clamping unit or a releasable clamping connection, after the gap width S of the gap has been adjusted.
 10. Diagonal fan according to claim 7, wherein the axial adjustment unit is designed as a screw connection with an adjusting screw as the adjustment element, or as a fastener connection with a tension rod as the adjustment element.
 11. Diagonal fan according to claim 7, wherein the adjustment element of the axial adjustment unit between the carrier plate and the motor engages with a driveshaft of the motor or with the carrier plate.
 12. Diagonal fan according to claim 7, wherein the adjustment element of the axial adjustment unit between the cover plate and a housing portion or an inlet nozzle of the intake unit is designed as an external thread on the cover plate, which engages with the housing portion or the inlet nozzle of the intake unit.
 13. Diagonal fan according to claim 1, wherein the axial adjustment unit has at least one adjustment element, whereby the carrier plate is adjustable with respect to the motor or the cover plate to the housing portion or to the inlet nozzle of the intake unit in a predetermined gradation.
 14. Diagonal fan according to claim 13, wherein the adjustment element is designed as a fitting pin, a fitting key or a fitting protrusion, which can be arranged into a stepped recess, into depressions that are arranged individually alongside one another or openings that have depths that are axially different from one another.
 15. Diagonal fan according to claim 13, wherein the adjustment element is designed as an adjusting screw or a tension rod, which is particularly provided between the carrier plate and the motor that drives the carrier plate, on which spacing elements having predetermined lengths is arranged.
 16. Diagonal fan according to claim 1, wherein the at least one axial adjustment unit is provided between the cover plate and a housing portion or on an inlet nozzle of an intake unit.
 17. Diagonal fan according to claim 1, wherein the at least one axial adjustment unit is provided between a motor cover and the motor or between a housing portion of the guide device and a motor cover that receives a motor.
 18. Diagonal fan according to claim 8, wherein the adjustment element of the axial adjustment unit is secured with a releasable clamping unit or a releasable clamping connection. 